1. Technical Field
The present invention relates to an umbilical member clamping device for clamping a plurality of umbilical members, which is used in an industrial robot.
2. Description of the Related Art
In an industrial robot, various umbilical members are attached to the body of the robot. Examples of the umbilical members include a cable for supplying power or signals to a motor for driving a joint shaft of the robot, and a tube for supplying power or cooling water to an external device such as a welding gun or hand attached to a tip end of an arm.
Umbilical member clamping devices for securing such umbilical members to a body of a robot have been known. The umbilical members secured to the body of the robot may receive a pulling force depending on movement of the robot. Thus, in order to tightly secure the umbilical members and to prevent the umbilical members from being damaged, the umbilical member clamping devices for securing the umbilical members via elastic bodies has been widely used.
FIG. 10 shows an umbilical member clamping device 50 according to a first related art. The umbilical member clamping device 50 includes a base member 51 attached to the body of a robot, a clamp member 53 secured to the base member 51 by bolts 52, and an elastic body 54 provided in a space defined between the clamp member 53 and the base member 51. The elastic body 54 is comprised of three elastic body blocks 541, 542, and 543. The elastic body blocks 541, 542, and 543 have a plurality of grooves each having a semicircular section, and are assembled so that a plurality of through-holes 55 are defined in the elastic body 54. Each through-hole 55 is sized in accordance with the dimensions of umbilical members 56 so that the through-holes 55 can receive the umbilical members 56, respectively. JP2013-202696A discloses an umbilical member clamping device for clamping umbilical members via such elastic body blocks.
FIG. 11 shows an umbilical member clamping device 50 according to a second related art. The umbilical member clamping device 50 includes an elastic body 54 provided so as to surround a bundle of a plurality of umbilical members 56.
In the umbilical member clamping device 50 according to the first related art, the through-holes 55 are formed in accordance with the shape and dimension of the umbilical members 56. Thus, a wide variety of elastic body blocks 541, 542, and 543 should be prepared to clamp the umbilical members 56 having different shapes or dimensions. This results in an increase in cost, and also results in increased dimensions of the umbilical member clamping device 50. In the umbilical member clamping device 50 according to the second related art, the umbilical members 56 may be collapsed by a pressing force F which is applied to the umbilical members 56 when the clamp member 53 is secured to the base member 51 (see FIG. 11).
Therefore, low-cost umbilical member clamping devices which can prevent umbilical members from deforming have been demanded.